Fluid filters are utilized to separate particulate matter that is dispersed in a fluid. For example, fluid filters are used to desalinate water, purify lubrication fluids in mechanical devices, and remove particular matter from air or other gaseous fluids. Examples of filters include U.S. Pat. No. 6,524,488, which describes a filtration media formed from at least one structured polymeric layer, wherein a structured surface is defined within the layer. Layers may be configured as a stack that has the structured surfaces defining a plurality of ordered inlets open through a face of the stack and corresponding ordered fluid pathways, thereby forming an ordered, porous volume. The ordered fluid pathways may be defined by a plurality of flow channels formed within the structured surfaces of the structured layers, or may be defined by a plurality of protuberances formed in an ordered pattern within the structured surfaces of the structured layers. Also, U.S. Pat. No. 7,282,148 describes an asymmetric filter membrane, and process for making the same. The membrane structure is physically robust and suitable for use in a wide variety of applications. The support membrane is may be comprised of material such as a porous silicon or a silicon oxide, and the separation membrane may be comprised of material such as a polymer, zeolite film, or silicon oxide. The process relies on steps adapted from the microelectronics industry.
Further, US 2012/0267249 describes a filter that includes a membrane having a plurality of nanochannels formed therein. A first surface charge material is deposited on an end portion of the nanochannels. The first surface charge material includes a surface charge to electrostatically influence ions in an electrolytic solution such that the nanochannels reflect ions back into the electrolytic solution while passing a fluid of the electrolytic solution. Methods for making and using the filter are also provided.